Syntax

FLAGs { $<$flag-statement$>$ } END
is invoked from the main level of X-PLOR. Note: certain energy terms that are initially off will be turned on automatically when statements related to this energy are invoked, but this is generally not the case.
$<$flag-statement$>$:==
EXCLude {$<$*energy-term*$>$ }
excludes specified energy-terms.
INCLude {$<$*energy-term*$>$ }
includes specified energy-terms.
$<$energy-term$>$:==
ANGL
specifies bond angle energy (default: on).
BOND
specifies covalent bond energy (default: on).
CDIH
specifies dihedral angle restraints energy (default: off).
DG
is a distance geometry restraint term (see Chapter 37) (default: off).
DIHE
specifies dihedral angle energy (default: on).
ELEC
specifies intramolecular electrostatic energy (default: on).
HARM
specifies a harmonic energy that restrains the positions of the molecule (default: off).
HBON
specifies explicit hydrogen-bond energy (default: off).
IMPR
specifies improper dihedral angle (e.g., chirality and planarity) energy (default: on).
NCS
specifies non-crystallographic positional restraint energy (default: off).
NOE
specifies distance restraints (see Chapter 20) (default: off).
PELE
specifies symmetry-related electrostatic energy (default: off).
PLAN
specifies planarity restraints energy (default: off).
PVDW
specifies symmetry-related van der Waals energy (default: off).
RELA
is a complete matrix relaxation effective energy term (see Chapter 39) (default: off).
VDW
specifies intramolecular van der Waals energy (default: on).
XREF
specifies crystallographic effective energy (default: off).

Xplor-NIH 2023-11-10